Retractable nose wheel



April 12, 1949- w. B. WESTCOTT, JR

RETRACTABLE NOSE WHEEL 3 "Sheets-sheaf. 1

Filed April 24, 1945 INVENTOR 4 WILLIAM B; wzsrcow m Q ATTORNEY April 12, 1949. w. a. WESTCOTT, JR

RETRACTABLE NOSE WHEEL 3 Shets-Sheet 2 Filed April 24, 1943 INVENTOR WILLIAM B WESTCOTT J'R ATTORNEY April 1949- w. B. WESTCOTT, JR 2,467,064

RETRACTABLE NOSE WHEEL Filed April 24, 1943 3 Sheets-Sheet 3 Iii v INVENTORY WILLIAM B. WESTCOTT JR.

ATTORNEY Patented Apr. 12, 1949 RETRACTABLE NOSE WHEEL William-B. Westcott Jr., Columbus, Ohio; assignor-to Gurtiss Wright Corporation, a. corporation of. Delaware Application April 24, 1943, Serial No. 484,448

15 Claims. (01. 244-102.)

This invention relates to retractablelandinggear and more particularly to collapsible struts used in connection therewith.

The usualcollapsiblestrut is not adaptable for use in airplanes providing only limited head space for the withdrawal: of the landing gear into the airplane, as for instance, where it is. used with landing gear adapted" tobe mounted in the nose of the airplane fuselage. Suchstruts are collapsible but are more often in use where there is considerable head space ofiered within the airplane, and within which to project the same. It is, therefore, the-obiectof the present invention to provide a collapsible strut-for use with landing gear wherein thememoers forming a part of the collapsible strut, through their motion, upon the landing gear being retracted, will fold. and occupy only minimum: space.

It is a more specific object of the invention to provide av retractable landing gear particularly adapted for connection to-the engine mountingot an airplane wherein the sam may be folded into a position under the engine mounting. and without the members of the strut entering or projecting into the confines of the mounting.

According to the present invention, the collapsible strut has beenmadeof'twomembers, one which carries a pivotable trunnionwith an opening'therein through which the other-of the members of the collapsible strut is slidable. The-other member, upon thestrut being collapsed, will slide collapsible strut; remains fixed at all:- times; the

movement of the. other: member; with respect thereto bein Permitted bythesliding connection of the one member with the: trunnion and the pivotal. movement of thetrunnionzitseif; Associ ated with. the trunnion; is a; pairof;1ocking:e1e. ments respectively axially disposed. in. openings in opposite ends of. thesameand: adaptedzto ex:- tend into the. opening; through: the; trunnion for locking engagement. with. the. member which:- is slidabletherethrough, whereby the: members; can

2 be locked in. their extended position. The trunnion retained in bearing members respectively carried on the legs of the bifurcated member and separable therefrom to permit the assembly of the trunnion thereto. Common means accessible tothe pilotis provided for'unlocking the collapsible members and for unlocking the landing gear from its raised. positionv to permit'the sameto be lowered.

For-other'objects' and for a better understanding of. the invention, reference may be had tothe following detailed description taken in connection with-theaccompanying drawing, in which Fig. lis. a phantom View, in elevation, of a part of an airplane structure: and of the engine mounting to which is: connected thelanding gear embodying the collapsible strut of the present invention.

Fig. \2 is a fragmentary plan view of the arrangement shown in'Fig; 1.

Fig. 3 is an enlarged fragmentary view, in elevation, of the collapsible strut and. illustrating by means of dotted lines, different positions of the strut at different stagesof movement of the same as it is. folded rearwardly to permit thev raising of. the; landing: gear.

Fig. 4 is still another enlarged. view, in elevation. taken: only at. the pivotal joint of the colla-psible members and similar to the showing of that portion of the same in: Fig. 3;

Fig, 5 is'an enlarged planview of the bifurcated member with the trunnion and'the locking means associated: therewith being insection and in such position asto; retain the slidable member of the collapsible. strut in its extendedior'locked position.

Referring now particularly to Figs. 1' and 2, there is shown a. phantom view ll. of the nose of an airplane extending from a point well forward of an. engine: mounting l2 and to a point rearwardly of a. firewall l3 having a downwardly inclined portion 14. The engine mounting ['2' has a usual ring l5 into which the engine is projected and. secured, and: which is carried on rearwardly extending. brace rods, each of the latter being secured at its-rearward end to a connecting plate member I! which isadapted to be attached to a bracketl I 8. on the fire-wall byafastening bolt l9:

To the ring 15 there is pivotally connected at 25, a. shock-absorbing strut 2| which has at its lower end a: spindle 22. with alanding'wheel 23 thereon. This spindle 22 can caster in a block 25 carried on. the end of a member 25 which is slidable in and out of a fiuid cylinder 26. This strut 2l' is actuated to and fromits lowered position by means of a fluid actuator or oleo strut 21 connected to the fire wall l3 by a bracket structure 28 and to a lug 29 on the shock-absorbing strut 2| below its pivot point 28. As the fluid actuator or oleo strut 29 is actuated, pivotal movement of the shock-absorbing strut 2| about the pivot point 20 is effected. An extension of the oleo. strut 21 will move the strut 2| to its operative or down position so that its wheel 23 will be in contact with the ground upon the airplane making its landing and upon the oleo strut 21 being retracted after the take-01f of the airplane, the strut 2| will be drawn into the body structure I of the airplane to assume its retracted position, shown in dotted lines 30 in Figs. 1 and 2.

As a means for locking the shock-absorbing strut 2| in its down position, there is provided a collapsible strut 32 embodying the features of the present invention. This strut 32 includes a stationary member 33 connected to laterally extending brackets 34' on the connecting plates H and to the ring by means of downwardly extended straps 35. These straps 35 connect with legs 36 of a bifurcated portion 31 to the forward ends of which is respectively connected bearing elements 38 between which there is provided a space. On the outer end of the bearing elements 38 there is respectively provided bearing openings 39 into which there is extended for rotational movement a trunnion 48 which has an opening 4| extending therethrough. This opening 4| is adapted to receive a tubular brace member 42 in a manner such as to permit it to slide therethrough. The member 42 at is lower end is connected to a lug 43 on the cylinder 26 of the shock absorbing strut.

The member 42 at its connecting end with the trunnion 40 has an enlarged head 44' adapted to abut against a shoulder 45 in the trunnion when the member 42 is extended from the member 33 as when the shock-absorbing strut 2| is in its lowered position. As the strut 2| is retracted, the member 42 is slid rearwardly through the trunnion 40 into the space between the legs 36 of the bifurcated portion 31 of the member 33. At the same time that this sliding movement has taken place, the trunnion is rotated in the bearing openings 39 so as to permit the folding of the member 42 up under the member 33, the head 44 of the member 42 describing something of an ellipse A, Fig. 3.

This sliding of the member 42 through the trunnion and the consequent rotation of the trunnion 42 is permitted only as locking elements 46in openings 41 of the trunnion are withdrawn so as to release the head 44 for movement away from the shoulder 45. These locking elements 46 are axially slidable in axially extended openings 41 and are normally held projected into the opening 4| by compression springs 48 in cup-shaped retainers 49. The cup-shaped retainer is internally threaded at 50 and is held against being unthreaded from the threaded portion ends 5| of the trunnion 40 by a fastening screw 52 which extends through the end 5| and into the wall axial opening 41. By so doing the screw 52 also serves to prevent rotation of the locking element by keying with an axially extending slot 54 in the locking element 46. On the inner ends of the locking members, there is provided a face portion 55 adapted to contact with an inclined face on the head 4'4 of the pipe 42. On the other side of the locking element 46 is a face portion 56 having less inclination than the surface 55 and serving as a means for the contact of the head member 44 as 4 it is returned forwardly through the trunnion 40.

These locking elements 46 have a stem 51 which extends through the cup retainer 49 and on the outer end of which is disposed a washer 58 and a nut 59. Under the washer 58 there is projected an arm 60 of a bell crank 6| which is pivoted at 62 on a laterally extending bracket 63 which is connected to the bifurcated portion 31 by fastening bolts 64. One of each pair of the latter serves as the means for the connection of a bracing strap 35 with the member 33 while one of said pairs serves for the connecting of one of the bearing elements 38 with one of the legs 36. The bell crank 6| is adapted to be actuated by the rearwardly extending connecting rods 65 which are connected to a lever 66 pivotable with respect to the aicraft structure about a pivot 61 and adapted to be operated by a hand lever 68 in the cockpit of the airplane and which is connected to an arm 69 of the lever 66 by a rod 15. The rod 65 may be adjusted in length by a screw adjustment 1| on the forward end near its connection with bell :crank 6|.

In order to lock the landing gear structure in its raised position, there is provided on the inclined portion of the fire wall I3 a pivot hook 13 adapted to hook under a lateral projection 14 on the shock-absorbing strut 2|. This hook 14 is operated by the same lever 66 that is utilized for the lock system associated with the collapsible strut, the former being connected with this lever 66 by a connecting link 15. With the hand lever 68 moved to one position or the other, either the collapsible strut will be locked to hold the landing gear in its down position or the landing gear will be locked to the fire wall l3 to hold the same in its raised position.

It should now be apparent that there has been provided a collapsible strut for landing gear wherein only minimum space is required for the collapsing of the strut as the shock-absorbing strut is pivoted rearwardly to its raised position. The head 44 of the member 42 will project only a small distance upwardly as the strut'is collapsed and outside of the confines of the engine mounting. It should also be apparent that there has been provided a novel arrangement which is associated with the trunnion itself for effecting the locking of the collapsible strut in its extended position.

While various changes may be made in the detail construction, it shall be understood that such changes shall be within the spirit and scope of the present invention as defined by the appended claims.

I claim as my invention:

1. In an airplane, a structure adapted for movement into and out of its operative position, a collapsible strut for retaining the movable structure in its operative position including two interconnected members, one of said members having a bifurcated portion, a trunnion rotatably connected to the bifurcated portion and with an opening therein in alignment with a space defined by the bifurcated portion, the other of said members being slidable through the trunnion opening and into the space defined by the bifurcated portion upon structure being moved, locking elements respectively axially movable in opposite ends of the trunnion and adapted to project into the opening therethrough for locking engagement with the other member to thereby effect locking together of the two members when extended with respect to each other, and

means :carried-::on:.the :Joifurc,ated:member.ziorropcrating :the .locking :elements'.

i2- .=In :an airplane, a :mainrstrut which :carries assurface-engaging element 'andzwhichjspivetaliy mountedz-for;swinging:movement to extendedzand retracted positions, arcollapsible 'strut fonholding the manrstrut :in:its ."extendedrposition, :said ,collapsible strut shaving stationary .and imovabl-e sections, meansrpivotediupon arfixedvams tofthe stationary :section :and .slidably rconnecting :the movablesection .forzpivotally sand slidably :conmeeting :the :movable .section to "the :stationary sect-ion :so :.that, .as :the main strut 1-iS "extended and retracted, the movable section of tithe i601 lapsible strut :may :move lengthwise and :swing about its ;.connection' with the stationary .8601310]?! in :the same:sense: in which thesmai-n: strut swings :abnut its pivotal. mounting, :andrmeans for'jlocking the :movable :and; stationary "sections =of ":Lthe acollapsible :strut against relative movement. in ethe extended position of :the .main 5513121113.

:3. :In :an airplane, a ;main pstrut which carries azsurfacee'engagingielementrand whichi isxpivotally mounted forznmvementito extend'edlands retracted positions, :a collapsible strut :for holdingithemain strut in its extended position, :said collapsible strut having stationary and :nnovable :sections, means pivoted'npon a. fixed axisttothe stationary 5601310111 and-islidably connecting themoveiblessection .':for :pivotally v: and ;slidab'1y :connecting :the movable :section'to the stationarysectionzso that, as rthenmain strut is extended: andzretracted, ith'e movable-sectionzofrthe rcollapsibleistrut 'may move lengthwise sand swing about its :connection with nthestationa-ry section infthezsamersenseinzwhich the main strut swings -.a/b 011l7"i'bSLDiVOtfilFTIIOllIltingwsaidcollapsiblestrutsections assumingia'zsubstantially :rectilinear relation in ithe extended position of the main strutrandzmeansztorrlocking .the-.movableiand stationary sections mizthe collapsible strut against relative .movement .iin *the extended :position ,of the .main strut.

A. In .an airplane, a main strut which marries -a-surfaceeengaging element. and :whic'lrisjpivotal'ly mountedzformovement toextendedandt'retracted positions,,a:collapsibles strut: for :holdingzthe imain strut :in its extended position, ;said rcoll'aps'i'bl'e strut having :stationary and movable 'tsections, a swivel carriedxby the v:outer ;end of therstat-ionary strut section-for movement with :respect-thereto and for *slidable engagement with :the inner send or :the movable section, said swivel :pcrmitting ttheimovable section to 1move lengthwise :and to swingiin' the same sense in which :Tthe main-strut swings pabout'its pivotaltmounting; and means for locking the imovable and stationary isections 0f the collapsible strut against-relative fmovement .in theextended position of the main strut.

:5. LIn-an airplane, a main strut vwh-ich carries a surface-engaging element and which ispivotally mounted for movement toextendeda-andretracted positions, acollapsible strut for-holding the main strut in its extended position, said collapsible strut having-stationary and ,movablesections, a

swivel-carried .bytheouter end of the stationary i strut sect-ions for movement with respect .thereto and for vslidable engagement with :the .inner .end .of the movable section, said swivel ,permitting the movable section to move lengthwise and to swing in the same sense in which .the :main J" strut swings about is pivotal mounting, zsaiducollapsible strut sections assuming a substantially rectilineainrelation inithe extended position of the main strut, and means for locking the mova- 6 :a'gainstxrelativez'movement'rinithe extendedwnsi tion of the main strut.

16. .Inzan :airplane, a ;main.-rstrut which :carries asurifa'ce eengaging' elementaand which is:piv.otall-y mounted for movement to extended and retracted positions, a "collapsible strut for :holding the main strut 'in its extended position, said 1001- lapsible istrut having :a stationary :section iformed :with Jiork extensions and :a -movable section, a .swivel .having journals :mounted in said forkvextensions and. being I formed :witha transverse bore for accommodating and movable :section, said swivel permitting the :movable section to'move lengthwiseinsaid 'boreand to swing in the same sense in which themain strut swings about its: pivotal mounting, and means for locking the "movable and stationary isections di the collapsible strut. against relativemovement-in the extended'position of the main strut.

"7. In an :airplane, a main strut which 7 carries asur'face engaging element and which ispivotally 'mounted formovementtoextendedand retractcd positions; a collapsible strut for holding-the main strut in its extended position, said collapsible s'truti having a stationary section formed with-fork extensions and a movable-section, a-swive1 having journals mounted in said \fork extensions and being "formed with a bore "foraccommodating said movable section, said swivelpermitting the movable section to move lengthwise in-said bore and 'to swing in the "same sense in which the main strut swings about its pivotal mounting, said "collaps'ible :strut sections assuming a substantially rectilinear relation in the extended position of the main strut,and;means for looking the movable and stationary sections -=o"f =the collapsible strut against relative movement in 'theextended position of the 1 main strut.

'8. Inan airplane,-a main strut Whicl1=:c-arr-ies *a sur'face engaging element and which is pivotally mounted for movement to extended and. retracted positions, a collapsible strut-for holding the-main strut in' its extended position, said collapsible strut having a stationary section formed -=wlth fork extensions and a movable section formed with a head, a swivel having journals-mounted in said "fork extensions, being formed with a "transverse here between said journals for accommodating said movable'section and having a seat iorsai'd head, said swivel permitting'the -movable section to "move lengthwise between said fork extensions and to 'swing-in'the same sense in which the-main strut swings about its pivotal mounting, and means for holding-said head against-said seat in the extende'd position of the main strut.

9. In an airplane, a main strut which carries asmfface engaging. element and which'is pivotall'y mounted for movement to' extendedand retracted positions, 'a collapsible strut .forholding the main strut iin its extended position, said collapsible strut having a stationary "section fformed with 'foik "extensions and a movable section 'formed withialhead, a swivel'havingjournals mounted in said fork extensions, being formed with .a transverse .bore'between said journals for accommodating said movable section an'd'having. a seat forssaidhead, said swivel permitting the movable sectionqtmmove lengthwise between said ifoik tensions-rand toiswing, in the same .sensein which the maimstrut. swings:aboutitspivotal mounting, and toppesed flocking elements which .are :engag-eabie with :said vhead for holding the ,latter against said seat in the extended positiomof .the

ble and stationaryesectionsaofitheacollapsible strut .276 mainstruhsaid-lockingelements,beingmetractable to permit said head to pass between them when the main strut is retracted.

10. In an airplane, a main strut which carries a surfaceenga'ging element and which is pivotally mounted for movement to extended and retracted positions, a collapsible strut for holding the main strut in its extended position, said collapsibie strut having a stationary section formed with fork extensions and a movable section formed with a head, a swivel having journals mounted in said fork extensions, being formed with a transverse bore between said journals for accommodating said movable section, having a seat for said head and permitting the movable section to move lengthwise between said fork extensions and to swing in the same sense in which the main strut swings abouts its pivotal mounting, said collapsible strut sections assuming a substantially rectilinear relation in the extended position of the main strut, opposed locking elements which are engageable with said head for holding the latter against said seat in the extended position of the main strut, said locking elements having beveled faces which exercise a wedging action upon said head, resilient means for biasing said elements toward a locking position, and means for withdrawing said locking elements to permit said head to pass between them when the main strut is retracted.

11. The combination with the engine mount of an airplane, of a main strut which carries a surface-engaging element and which is pivotally connected to said engine mount for movement to extended and retracted positions, a collapsible strut for holding said main strut in its extended position, said collapsible strut having stationary and movable sections, means pivoted upon a fixed axis to the stationary section and slidably connecting the movable section for pivotally and slidably connecting the movable section to the stationary section so that, as the main strut is extended and retracted, the movable section of the collapsible strut may move lengthwise and swing about its connection with the stationary section in the same sense in which the main strut swings about its pivotal connection with said engine mount, and means for locking the movable and stationary sections of the collapsible strut against relative movement in the extended position of the main strut.

12. The combination with the engine mount of an airplane, of a main strut which carries a surface-engaging element, said strut having angularly-extending, diverging arms whichare pivotally connected to the engine mount so that said strut may be moved to an extended position in which said surface-engaging element is lowered and located ahead of the engine mount and to a retracted position in which it is elevated and located behind the engine mount, a collapsible strut for holding said main strut in its extended position, said collapsible strut having stationary and movable sections, means for pivotally and slidably connecting the movable section to the stationary section so that as the main strut is extended and retracted, the movable section of the collapsible strut may move lengthwise and swing about its connection with the stationary section in the same sense in which the main strut swings about its pivotal connections with said engine mount, and means for locking the movable and stationary sections of the collapsible strut against relative movement in the extended position of the main strut.

13. The combination with the engine mount of an airplane, of a main strut which carries a surface-engaging element, said strut having angularly-extending, diverging arms which are pivotally connected to the engine mount so that said strut may be moved to an extended position in which said surface-engaging element is lowered and located ahead of the engine mount and to a retracted position in which it is elevated and located behind the engine mount, a collapsible strut for holding said main strut in its extended position, said collapsible strut having stationary and movable sections, means for connecting the stationary section to, and for supporting it below, said engine mount, means for pivotally and slidably connecting the movable section to the stationary section so that, as the main strut is extended and retracted, the movable section of the collapsible strut may move lengthwise and swing about its connection with the stationary section in the same sense in which the main strut swings about its pivotal connections with said engine mount, said collapsible strut sections assuming a substantially rectilinear relation in the extended position of the main strut, and means for looking the movable and stationary sections of the collapsible strut against relative movement in the extended position of the main strut.

14. The combination with the engine mount of an airplane, of a main strut which carries a surface-engaging element, said strut having angularly-extending, diverging arms which are pivotally connected to the engine mount so that said strut may be moved to an extended position in which said surface-engaging element is lowered and located ahead of the engine mount and to a retracted position in which it is elevated and located behind the engine mount, a collapsible strut for holding said main strut in its extended position, said collapsible strut having a stationary section formed with fork extensions and a movable section, means for connecting the stationary section to, and for supporting it below, said engine mount, a swivel having journals mounted in said fork extensions and being formed with a bore between said journals for accommodating said movable section, whereby, as the main strut is extended and retracted, the movable section of the collapsible strut may move lengthwise in said bore and swing in the same sense in which the main strut swings about its pivotal connections with said engine mount, said collapsble strut sections assuming a substantially rectilinear relation in the extended position of the main strut, and means for locking the movable and stationary sections of the collapsible strut against relative movement in the extended position of the main strut.

15. In an airplane, a landing gear shock strut comprising telescoping inner and outer sections, the inner section having a pivot connection to the aircraft for swinging of the shock strut between extended and retracted positions, the outer section carrying a surface-engaging element, a member pivoted to the aircraft on an axis substantially parallel to the axis of said pivot connection, a brace strut pivoted to said inner section of the shock strut and slidably connected with said pivoted member, and latch means for holding the brace strut against sliding movement relative to the pivoted member in at least one of said positions of the shock strut.

WILLIAM B. WESTCOTT, JR.

(References on following page) 9- REFERENCES crrnn Number The following references are of record in the 2180462 file of this patent:

UNITED STATES PATENTS 5 T INumber Number Name Date 7 291 1,553,249 Legrain Sept. 8, 1925 513,020 1,812,211 McCrea June 30, 1931 1 Name mu De SeverskY Nov. 21, 1939 FoREIGNiiiTENTs Country Date I Great Britain 19 09 Great Britain Feb. 15, 1940 

